Toxicological response and bioaccumulation of strontium in Triticum durum (Nachit) and Triticum aestivum (Ibtissam)

Abstract

The present study examines the toxicological effects and bioaccumulation of strontium (Sr²⁺) in two Moroccan wheat species, Triticum durum (Nachit) and Triticum aestivum (Ibtissam). Germination rates and seedling growth parameters were evaluated under Sr²⁺ concentrations of 0, 10, 100, and 1000 mM. Results revealed a significant decline in germination rates as Sr²⁺ concentrations increased, with T. aestivum showing higher sensitivity compared to T. durum. Low Sr²⁺ concentrations (10 mM) initially promoted stem growth in T. aestivum, but growth declined sharply at higher concentrations. Both species sustained growth at moderate Sr²⁺ concentrations (100 mM), but experienced a substantial reduction at 1000 mM, with T. durum demonstrating slightly better tolerance. Elevated Sr²⁺ concentrations notably affected root length and stem branching, indicating severe phytotoxic effects. Enzyme activity assays showed that at low Sr²⁺ concentration (10 mM), GST, CAT, POD, and SOD activities were similar to the control. At moderate concentrations (100 mM), GST and POD activities increased, suggesting enhanced detoxification. At high concentrations (1000 mM), all enzyme activities were significantly elevated, reflecting a robust antioxidative defense mechanism. This study provides valuable insights into the toxicological impacts and physiological responses of these wheat species to Sr²⁺ stress.